Circuit interrupter with arcextinguishing means



March 4, 1952 R. P. BALLOU 2,588,195

CIRCUIT INTERRUPTER WITH ARC-EXTINGUISHING MEANS Filed Sept. 17,- 1948 IN V EN TOR. RICHARD H. BALL 00' ATTORNEY Patented Mar. 4, 1952 CIRCUIT INTERRUPTER WITH ARC- EXTINGUISHING MEANS Richard P. Ballou, Hartf Federal Electric Prod N. J., a corporation rd, Conn., assignor to acts Company, Newark,

Application September 17, 1948, Serial No. 49,729

13 Claims. 1

This invention relates to electric switches or other circuit interrupters, and more particularly to circuit interrupters provided with are extinguishing means.

Materials which are considered best suitable for electric contacts or current conductors are not usually best suitable as arc-interrupting material. For example, copper and silver are good current-carrying materials, because of their low resistance, while such materials as carbon, tungsten, cadmium-silver and other alloys are recognized as good arcing materials. For this reason, circuit breakers frequently include two sets of contacts, one set which is provided for carrying the current being arranged to open before the set which is intended to interrupt the arc. While this arrangement is usually satisfactory as appliedto large circuit breakers, switches, or other circuit interrupters, such arrangement is expensive and complicated when applied to small circuit breakers or switches.

One of the objects of the present invention is the provision of a circuit interrupter with improved arc-interrupting means without adding substantially to the size or cost of the switch or other circuit interrupter and without sacrificing the advantages of such current-carrying mate rials as silver, copper, etc.

The above and other objects, features and advantages of the present invention will be fully understood from the following description considered in connection with the accompanying illustrative drawings.

In the drawings:

Fig. 1 is a side view of a switch embodying the present invention;

Fig. 2 is a front view thereof Fig. 3 is a sectional view of parts of the switch, in the closed condition of the latter, on the line 33 of Fig. 1;

Fig. 4 is a view similar to Fig. 1, showing a modification.

The circuit interrupter, here shown as a switch of the knife-blade type, comprises an insulation base l0 provided with a hinge-jaw l2, a contactjaw l4, and a movable contact member 16 which is pivotally secured to the hinge-jaw I2 and is engageable with and disengageable from the contact-jaw I4 for closing and interrupting the electric circuit. Jaws i2 and i 4 and the movable contact member I6 are made of copper or other good current-conducting material. Said jaws I2 and I4 are carried by parts 48 and 20, respectively, which are secured to base [0 and are provided with suitable terminals here shown for securing the two as terminal screws 22 and 24 respectively. As here shown the movable contact member I6 is in the form of a blade having the spaced hinge parts 25 and 26 which firmly engage the hingejaw l2 at the opposite sides thereof, said parts being pivotally secured to said jaw in any suitable way as by a pivot pin or rivet 28. The outer end of the movable contact member I 6 is provided with the laterally spaced parts 30 and 32 arranged to firmly engage the companion contact member or jaw 14 at the opposite sides thereof.

In accordance with the present invention, the movable contact member 16 is provided with an arcing-contact member 34, as shown in Fig. 1 or with a plurality of such members 34 as shown in Fig. 4. The arcing member 34 shown in Fig. l is mounted on movable contact member IS in electrically insulated relation thereto, in any suitable way, as by a bracket or support 36 which is formed of insulation material and secured to the intermediate portion of the movable contact member in any suitable way as by rivets 38. The latter may be the rivets which are provided parts of the contact member 16 to each other. As shown in Fig. 1, arcing member 34 is secured to insulation member 36 by one or more rivets 40. Arcing member 34 is provided with an opening 42 for the projection therethroug-h of the stationary contact member or contact jaw [4 when the switch is closed. Said arcing member is preferably made of cadmium or other material which is suitable for an arcing contact and which also has a deionizing effect on the arc. It will be understood however that said arcing contact member may be formed of any other suitable metal or of any other suitable material.

The arc-quenching action of member 34 is illustrated in Fig. 1. When the switch is opened, under current-carrying conditions such that the current is strong enough to form an are upon opening of the switch, such are tends to rise, due to the heat thereof, and by reason of the provision of the arc-interrupting member 34 said are is divided into a plurality of arcs indicated at Al and A2, formed respectively between contact member I4 and arc-interrupting contact member 34 and between said arc-interrupting member and movable contact member It. When, as shown in Fig. 4 the switch is provided with a plurality of arc-interrupting contact members 34, the are drawn between contact members l4 and it, upon opening the switch is divided into a corresponding number of arcs indicated at Al,

3 A2, and A3. In Fig. 4, the arcing members are insulated from each other and from contact member 16 by the insulation support 36A.

It will be understood by those skilled in the electrical art that the sub-division of the are drawn between the relatively movable contact members of the switch greatly aids in extinguishing the arc, and it will also be understood that the arc-extinguishing action is enhanced by the cooling action of the arc-interrupting member or members 34 on the arc, since members 34 do not carry any current when the switch is closed and are therefore comparatively cold. Also, when in accordance with the preferred embodiment of the invention, arc-interrupting contact members es are formed of cadmium or other deionizing material, the arc-extinguishing action i improved.

It will be understood that while the invention has been illustrated as applied to a switch of the knife blade type, said invention may be applied to other. types of switches and in general to various circuit breakers and makers or circuit interrupters. Accordingly the invention is not to be limited to any particular type of switch, it being understood that the type of switch shown is only illustrative of the invention but not in limitation thereof. Various changes in the details of construction and in the arrangement of parts may be made without departing from the underlying idea or principles of the invention within the scope of the appended claims.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

l. A circuit interrupter comprising a first contact member, a second contact member whichis movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing contact member electrically insulated from said contact members, said arcing contact member being in fixed disposition relative to said second contact member and movable with said second contact member in the path of movement of said second contact member in position between the latter and said first contact member whereby an arc drawn between said contact members when they are disengaged is subdivided into a plurality of arcs.

2. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing-contact member bodily carried by said second contact member and insulated therefrom, said arcing-contact member being mounted. in position for movement in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member, said arcing-contact member being free of engagement with said first contact member when the latter is engaged .by said second contact member.

3. A circuit interrupter comprising a first contact member, a second contact member which is movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing contact member electrically insulated from said contact members and movable with said second contact member in the path of movement of said second contact member in position between the latter and said first contact member whereby an are drawn between said contact members. when they are disengaged is subdivided into a plurality of arcs,

said arcing contact member having an opening through which said first contact member projects when the latter is engaged by said second contact member.

4. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing-contact member carried by said second contact member and insulated therefrom, said arcing-contact member being mounted in position for movement in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member, said arcing contact member having an opening through which said first contact member projects when the latter is engaged by said second contact member.

5. A circuit interrupter comprising a first contactmember, a second contact member which is movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing contact member electrically insulated from said contact members and movable with said second contact member in the path of movement of said second contact member in position between the latter and said first contact member whereby an are drawn between said contact members when they are disengaged is subdivided into a plurality of arcs, said arcingcontact member being formed of deionizing material.

6. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and an arcing-contact member carried by said second contact member and insulated therefrom, said arcing-contact member being mounted in position for movement in the space between said first and second contact members during the movement of said contact member from engagement with said first contact member, said arcingcontact member being formed of deionizing material.

'7. A circuit interrupter comprising a first contact member, a second contact member which is movable into and out of engagement with said first contact member for makin and breaking the circuit, and an arcing-contact member electrically insulated from said contact members and movable with said second contact member in the path of movement of said second contact member in position between the latter and said first contact member whereby an are drawn between said contact members when they are disengaged is subdivided into a plurality of arcs, said arcing-contact member being formed of metal and having an opening through which said first contact member projects when the latter is engaged by said second contact member.

8. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, a support fixedly carried by said second contact member and insulated therefrom, and an arcingcontact member carried by said support in position for movement between said first and second contact members, said arcing-contact member being free of engagement with said first contact member when the latter is engaged by said second contact member.

9. A circuit interrupter'comprising a first-con tact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, a support fixedly carried by said second contact member and insulated therefrom, and a plurality of spaced insulated arcing-contact members carried by said support in position for movement between said first and second contact members.

10. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and a plurality of spaced arcing-contact members insulated from each other and from said second contact member, said arcing-contact members being bodily carried by said second contact member for movement with the latter in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member, said arcing-contact members being free of engagement with said first contact member when the latter is engaged by said second contact member.

11. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and a plurality of spaced arcing-contact members insulated from each other and from said second contact member movable with the latter in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member, each of said arcing members having an opening through which said first contact member projects when the latter is engaged by said second contact member.

12. A circuit interrupter comprising a first contact member, a second contact member movable into and out of engagement with said first contact member for making and breaking the circuit, and a plurality of spaced arcing-contact members insulated from each other and from said second contact member movable with the latter in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member, each of said arcing members having an opening through which said first contact member projects when the latter is engaged by said second contact member, said arcing members being carried by said second contact member, said arcing-contact members being free of engagement with said first contact member when the latter is engaged by said second contact member.

13. A circuit interrupter comprising a first contact member, a second contact member movable about a fixed pivot point into and out of engagement with said first contact member for making and breaking the circuit, and an arcing-contact member having a center of rotation which coincides with said pivot point of said second contact member, said arcing-contact member being actuated by said second contact member and insulated therefrom, said arcing-contact member being mounted in position for movement in the space between said first and second contact members during the movement of said second contact member from engagement with said first contact member.

RICHARDP. BALLOU.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 589,582 Smith et al Sept. 7, 1897 1,993,273 Hammerly Mar. 5, 1935 

